Referenced string is not real string (cannot be used as dict key, doesn't equal to string)

[adaamz]

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Describe the bug

To Reproduce

Example schema:

openapi: "3.0.0"
info:
  version: 1.0.0
  title: File endpoint
paths:
 get_file:
    parameters:
      - $ref: "#/components/schemas/FileRequest"

components:
  schemas:
    FileHash:
      type: string
      min_length: 32
      max_length: 32
      regex: "^[a-fA-F\d]{32}$"
    FileRequest:
      type: object
      required:
        - file_hash
      properties:
        file_hash:
          $ref: "#/components/schemas/FileHash"

Used commandline:

$ datamodel-codegen file.yml

Generated python code:

class FileHash(BaseModel):
    __root__: str = Field(..., max_length=32, min_length=32, regex="^[0-9a-fA-F]+$")

class FileRequest(BaseModel):
    file_hash: FileHash

Python usage

file_hash = "a"*32
f = FileRequest(file_hash=file_hash)

assert f.file_hash == file_hash) # does not equal

d = dict()
d[f.file_hash] = "asdf" # throws TypeError: unhashable type: 'FileHash'

Expected behavior

• original string equals with field
• can be used as key in dict

Version:

• OS: linux
• Python version: 3.9
• datamodel-code-generator version: 0.11.14

[koxudaxi]

@adaamz I'm sorry for the slow response. We should use __root__ attribute for usecase.

assert f.file_hash.__root__ == file_hash # does not equal

d = dict()
d[f.file_hash.__root__] = "asdf" # throws TypeError: unhashable type: 'FileHash'

[adaamz]

yeah, i know this "workaround"... but is it possible to use the property as standard string? 🤔

[koxudaxi]

If the code-generator provides the workaround...

class FileRequest(BaseModel):
    file_hash: str = Field(..., max_length=32, min_length=32, regex="^[0-9a-fA-F]+$")

Or

FileHash = str

class FileRequest(BaseModel):
    file_hash: FileHash

we should choice validation or Defined Type

[adaamz]

If I can choose combination then it would be probably best 😁

FileHash = str

class FileRequest(BaseModel):
    file_hash: FileHash = Field(...)

[rbuckland]

@koxudaxi is this something you are looking at introducing ? a feature

effectively collapsing single primitive types, into their "base" type on the field, in a parent class

[koxudaxi]

@rbuckland

effectively collapsing single primitive types, into their "base" type on the field, in a parent class

Could you explain the way?

[koxudaxi]

I have released the new version as 0.14.1. The version has this option.

 --collapse-root-models
                        Models generated with a root-type field will be
                        merged into the models using that root-type model